Effects of short-term, high-frequency repetitive transcranial magnetic stimulation to bilateral dorsolateral prefrontal cortex on smoking behavior and cognition in patients with schizophrenia and non-psychiatric controls.

BACKGROUND: High rates of tobacco smoking and smoking cessation failure in schizophrenia may be related to prefrontal cortical dysfunction. Novel treatment options for tobacco use disorder are needed given the limited efficacy of current pharmacotherapies. Preliminary evidence suggests high-frequency repetitive transcranial magnetic stimulation (rTMS) to bilateral dorsolateral prefrontal cortex (DLPFC) may suppress tobacco craving in smokers with schizophrenia. The goal of this study was to determine effects of rTMS for tobacco craving and cognition using a short-term (3-day) human laboratory paradigm. METHODS: Bilateral active (20Hz) versus sham rTMS stimulation was administered in a counterbalanced, double-blind, cross-over design to thirteen smokers with schizophrenia and n=14 non-psychiatric smoking controls. Participants were studied at baseline (smoking satiated), after 16h of smoking abstinence, and after smoking reinstatement. Primary outcome measures included tobacco craving, withdrawal and cognition. RESULTS: Overnight abstinence produced a significant increase in tobacco craving and withdrawal, and impaired verbal memory and visuospatial working memory in both diagnostic groups; these effects were reversed with smoking reinstatement. However, active rTMS did not modify this pattern of results. Moreover, active versus sham rTMS had no significant effects on cognitive outcomes, and was not associated with significant adverse events. CONCLUSIONS: Our preliminary findings suggest that short-term rTMS administration may not be sufficient enough to modify cognition, craving, and withdrawal outcomes in smokers with schizophrenia (NCT00736710). Longer-term, controlled treatment studies examining effects of rTMS on smoking behaviors and cognition in schizophrenia are warranted.

Co-morbid tobacco use disorder and depression: A re-evaluation of smoking cessation therapy in depressed smokers.

BACKGROUND AND OBJECTIVES: To provide a critical evaluation of nicotine use disorder co-morbidity in persons with major depressive disorder (MDD) or its subsyndromal presentations. We focus on how a diagnosis of current or past MDD may shape access to smoking cessation therapy, and highlight the unique challenges that this group of smokers has to overcome to receive adequate treatment. METHODS: A literature search was performed using PubMed for studies published between January 1995 and March 2015 using the following keywords and combination of keywords (co-morbidity, co-occurrence, and dual-diagnosis) and (nicotine dependence, cigarette smoking, tobacco dependence, tobacco use disorder) and (depression, major depression, unipolar mood disorders) and (self-medication). A total of 93 articles were identified. Of these, 31 studies were included in the analysis. RESULTS: We found that: a) depressed smokers are motivated to quit; b) smoking cessation does not exacerbate symptoms of depression; c) depression does not have a negative impact on smoking cessation outcomes, and d) the self-medication hypothesis does not account for tobacco dependence and depression co-morbidity. DISCUSSION AND CONCLUSIONS: Our review of the relevant evidence suggests the importance and clinical significance of undertaking smoking cessation treatment for depressed smokers. SCIENTIFIC SIGNIFICANCE: Our findings support the need for increased attention to developing and implementing smoking cessation treatments for depressed smokers. SCIENTIFIC SIGNIFICANCE: Our findings support the need for increased attention to developing and implementing smoking cessation treatments for depressed smokers.